1. Field of the Invention
This invention relates to an inventive structure of spring driving musical movement reduction device, and in particular, to a gear fixed base formed from project plastic material of a spring driving musical movement reduction device; the inventive structure uses the plastic elasticity to make the musical movement moving more stable, to reduce noise, to rise production efficiency and the quality of the musical movement.
2. Description of the Prior Art
Referring to FIG. 1 and FIG. 1(A), the characters of the prior art gear fixed device of the spring driving musical movement reduction device are: installing a friction unit 12, a bilateral gear 13 in a support frame set 11 made by punching an iron plate therein, and parallelizing a step spur gear 14 in a shaft bracket 15 of said support frame set 11, then riveting said shaft bracket 15; the material of said support frame set 11 is iron, and the collocated step spur gear 14 is made with project plastic material; the main composed disadvantages are:                (1) The ironed support frame set 11 easily produces featheredges upon pouching, which effects the movement of said bilateral gear 13 and said step spur gear 14, also accelerates the attrition of each gear;        (2) Said support frame set 11 also easily becomes deformed during the electroplating progress, which makes the step spur gear 14 hard to be installed and cause noise upon moving;        (3) To avoid the step spur gear 14 slip, the shaft bracket 15 needs to be riveted through quadratic process, however the shaft bracket 15 easily causes variable due to over pressing to make the step spur gear 14 rotate not smooth or even could not rotate, which causes whole structure produce disadvantages.        
With respect the prior art gear fixed device of the spring driving musical movement reduction device, please also refer to the structure showing as FIG. 2 and FIG. 2(A), which parallelizes a step spur gear 21, a friction unit 22 and a bilateral gear 23 in a gear concave groove of a musical movement base 21, and covers up a plastic spring cover 25 to make an extension portion 26 and another extension portion 27 of said spring cover 25 mutually cooperate to press a step spur gear 21; however, the main composed disadvantages are:                (1) The step spur gear 21 could not be effectively pressed due to the spring cover 25 deformed, which effects said step spur gear 21 move regularly.        (2) To fix the step spur gear 21 needs to use an extension portion 28 of the spring cover 25 to rivet and fix, however, the extension portion 28 often becomes deformed due to very complicated shape to cause pressing default.        
This shows, there still exits many defaults in manufacturing components, fabricating process and the quality after fabricating about the prior art structure of the gear fixed device of the spring driving musical movement reduction device; accordingly, the above-described prior art structure is not a perfect design and has still many disadvantages to be solved.
The inventor has noticed the various disadvantages associated with the conventional structure of the spring driving musical movement reduction device and thought to improve it, and after having carried out an intensive study for many years, has successfully developed the inventive structure of the spring driving musical movement reduction device.